html {
    font-family: sans-serif;/* 1 */
    -webkit-text-size-adjust: 100%;/* 2 */
}

html, body {
    padding: 0;
    margin: 0;
}

#mail-content {/*  padding: 0;*/
    margin: 0;
}

:root {-
    -primary-color: #3498db;-
    -secondary-color: #2c3e50;-
    -light-bg: #f8f9fa;-
    -dark-bg: #2c3e50;-
    -light-text: #333;-
    -dark-text: #f8f9fa;-
    -card-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);-
    -card-hover-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);-
    -border-radius: 8px;
}


h1 {
    font-size: 1em;
    font-weight: bolder;

}

h2 {

}

h1::before {
    content: "🔗";
    margin-right: 5px;
}


/**
* ref参考资料
*/


.Ref {
    background-color: white;
    border: 1px solid gray;
    margin: 1px 3px;
    padding: 1px 3px;
    border-radius: 3px;

    box-shadow: var(-
    -card-shadow);

overflow: hidden ;

transition: transform 0.3

s, box-shadow 0.3

s ;

display: flex ;

flex-direction: column ;

height: 100% ;
}

.RefContent {
    color: #666;
    line-height: 1.5;
    margin-bottom: 15px;
    flex-grow: 1;
}

.RefUrl {
    font-size: 0.85rem;
    color: var(-
    -primary-color);

word-break: break-all ;

display: flex ;

align-items: center ;
}

.RefUrl::before {
    content: "🔗";
    margin-right: 5px;
}

.RefTitle {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1px;
    color: var(-
    -secondary-color);

line-height: 1.4;
}


/**
* 知识点
*/

.Unit {
    border: 1px solid gray;/*    width: 100%;*/
    background-color: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    display: flex;
    flex-direction: column;
    margin: 1px 3px;
    padding: 1px 3px;
    border-radius: 3px;
    overflow: hidden;
}

.UnitTitle {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1px;
    color: var(-
    -secondary-color);

line-height: 1.4;
}

.UnitContent {
    color: #666;
    line-height: 1.5;
    margin-bottom: 1px;
    flex-grow: 1;
}